泥炭阴燃是森林地下火的主要燃烧形式之一,研究泥炭的热解规律对认识其阴燃机理及地下火蔓延机理有重要意义.本文使用荧光光谱分析技术测定了我国东北林区一种典型泥炭样品的主要元素组成,并使用热重-差热分析(TG—DTA)技术研究了泥炭样品在惰性气氛中的热解规律.实验结果表明,泥炭样品主要由45种元素构成.从常温到1073K高温的升温过程中,泥炭样品的质量损失过程可以分为三个阶段,依次为水分损失阶段、有机质热解阶段和矿物质分解阶段.对于泥炭阴燃密切相关的有机质热解阶段,结合热分析动力学理论和优化计算方法,建立了描述泥炭有机质热解动力学规律的三组分叠加反应模型.
Peat smoldering is one of the main combustion modes of forest ground fires. Research into the pyrolysis kinetics of peat is an essential step in studying the peat smoldering mechanism and ground fire behavior. We measured the elemental composition of one typical peat sampled from the northeast forest zone of China by means of spectrofluorometry and studied the pyrolysis characteristics of peat with thermogravimetry-differential thermal analysis (TG-DTA). Results show that the peat sample is composed of more than 45 elements. The pyrolysis process of peat may be divided into three stages, i.e., dehydration, organic matter pyrolysis and mineral decomposition. Because organic matter pyrolysis played an important role in peat smoldering, the pyrolysis kinetics of organic matter was determined. Using thermal kinetic analysis theory and optimization methods, the model that three-component react parallelly was established to describe the scheme of peat pyrolysis. We found that the scheme containing three-parallelreactions could describe the pyrolysis kinetics very well.